Opposing Viewpoints is a database of short essays on different sides of topics. Each issue page has links to their essays, as well as links to academic articles, news, reference works, and statistics on the topic.
Remember to watch for bias in your resources. Most resources will have some sort of bias (particularly with such a controversial subject), it can have negligible impact on the work or impact all aspects of it. Bias will not necessarily invalidate a resource, but bias can influence authors' reference selections and how they interpret results.
Detecting Bias: Read these versions of some sentances from the first page:
It was greatly bolstered by the 1998 Lancet paper by Andrew Wakefield that showed autism was caused by the measles, mumps and rubella vaccine. While his paper were declared to be wrong, they are still cited by those who believe in the connection.
It was greatly bolstered by the 1998 Lancet paper by Andrew Wakefield that alleged a measles, mumps and rubella vaccine with autism. While Wakefield and his paper were shown to be fraudulent, they are still cited by those who believe in the hoax.
These sentances show obvious biases. Not all biases will be that easy to detect: just because the bias is not obvious does not mean it is not there.